Battery and magneto switch shield



June 5, 1945. A. HALLETT BATTERY AND MAGNETO SWITCH SHIELD Filed June 15, 1942 IN VEN TOR.

ALFRED 4 1441.577;

A TTORNEYS.

Patented June 5, 1945 BATTERY AND MAGNETO SWITCH SHIELD Alfred Hallett, Los Angeles, -Calif., minor to Hallett Manufacturing Calit, a copartnership Application June 15, 1942, Serial No. 447,076

3 Claims.

This invention relates to the shielding and protection of electrical systems for internal combustion engines and is an improvement over my copending application Serial No. 427,621, filed January 21, 1942, for Shielding for electrical systems.

Free electrical radiations from ignition systems of internal combustion engines used in proximity to radio receiving apparatus are picked up in such apparatus and interfere with reception. This is a serious factor in the operation of airplanes, motorboats, submarines, military land vehicles, and all other types of mobile transportaticn employing radio equipment as well as in stationary installations in proximity to radio equipment.

Having made a general disclosure of an improved form of shielding and terminals therefor in my said copencling application, it is an object of my present invention to provide more specifically a novel form of shield for a battery and magneto switch utilizing in connection'therewith the form of terminal disclosed in theaforesaid copending application.

Another problem arises in connection with the exposure of the elements of ignition systems to weather, oil and gas leakage and the like. Under heavy duty and adverse weather or operating conditions moisture, water, oil and gas may be deposited on the switches, terminals, etc. unless protected by moisture-proof and water-proof enclosures. Inasmuch as cables must lead to var ious parts of the switches such protective means should include the regions where the cables enter the protective housing.

It is therefore another object of my invention to provide an electrical shielding which combines the function of physical protection to the elements of the switch against weather and other adverse operating conditions which contribute to failure of the switch, deterioration of insulation, connections, etc.

It is a further and more specific object of my invention to provide a metallic shielding for the battery and magneto switch of an ignition systern which completely encloses and grounds the same, avoiding openings or cracks through which electrical radiations might escape, effecting improved electrical connections at the terminals and physical protection of the switch against the external conditions described.

It is a still further and more particular object of my invention to provide a novel form of metallic shield for a battery and magneto switch which can be applied to the standard or conven- Company, Inglewood,

tional form of switch without altering the latter, and enable the assembly to be installed on a panel or dash with but slight change from the standard installation.

These and other objects of my invention will be made more apparent from a consideration of the full description and drawing.

In the drawing:

Figure 1 is a vertical cross-sectional view of my novel shield applied to a battery and magneto switch, such for example as a standard Halscottswitch.

Figure 2 is a reduced front view of the same, as shown by the arrow 2 of Figure 1.

Figure 3 is a rear view of the same taken on the line 3-3 of Figure 1.

Figure 4 is a vertical cross-sectional view of a modified form or shield adapted to a different style switch, such for example as a standard Chrysler-switch.

Referring to they form of assembly shown in Figures 1 to3, I show a standard battery and magneto switch in enclosed within a metallic housing Ii mounted upon a dash or panel l2, and utilizing terminals i3.

The switch I0 contains a standard contact mechanism, not illustrated, located within a switch casing l4, the latter oi which is formed with a mounting-flange iii and through which operates the rotating spindle i i of a switch han die l'i.

My shield housing ii of materi having substantially high conductive proper ties, comprises a substantially cylindrical box it with opening it for access to the connections hereinafter described, the opening being closed by a flat plate 20, which may be attached to the he i 8 by screws 2 i. Optionally a gasket iii? may be used to seal the closure plate Ell upon the box.

I'he box it is open at the from; to receive the switch casing and the opening is bounded by an annular flange 25 which is tapped at 26 to accommodate bolts 27 by which the assembly is mounted upon the panel or dash i2. ilhe wall of the box i8 is enlarged at spaced points by bosses 28 which are tapped and threaded to accommodate screws 29 by which the flange i of the switch is securely mounted upon the shield housing. It will thus be seen that no alteration of the switch is necessary for installing it in the manner described.

Standard switch connections 39 are employed to which are connected cabies 35, the latter comprising a conductor 35a, insulating 35b and metal shielding 3B.

The shielding illustrated here is in the form of a woven metal sheathing but a tubular enclosure or other equivalent shielding for the cable 35 may be employed.

All of the terminals are of the same character. Each comprises a metal collar 31 formed with an annular shoulder 38 threaded into an opening 39 in the end of the shield housing.

This collar has an internal annular ledge 40. snugly fltting within the collar is an insulator 4| having a shoulder 42 seating onthe ledge 40, and being formed also with a beveled seat 43 at the upper end. Resting in this seat is a frusto conical insulating gland 44 preferably of soft rubber. A metal bushing 45 having a cylindrical portion through which the cable extends and a flat disc at the lower end is seated on the upper face of the gland 44. It is preferable that the cylindrical portion of the bushing be inserted between the cable shielding 36 and the insulation 35b of the cable. The lower end of the shielding 36 should be spread out over the disc portion Of the bushing and a ferrule 41 having a flange at its lower end rests upon the out-turned shielding and serves to center the cable. A threaded cap #8 screws down on the collar 31 to secure the various parts tightly in place.

In the modified form shown in Figure 4 the main portion or base of the shield housing is numbered 50 and is formed with an open front to receive the switch casing and this opening is bounded by an annular flange tapped at 52 to accommodate bolts 53 by which the housing is clamped upon the panel or dash [2a.

The switch Illa which is of a different typ and is here illustrated as a standard Chrysler switch has contact means, not illustrated, located within the tubular casing 54 which is threaded at 55 and also provided at its outer end with a mounting flange 56. A nut 51 operating on the threads 55 serves to clamp the switch upon the flange 5| of the shield housing. An ignition key 59 is illustrated in dotted lines. Switch connections 30a are shown at the rear end of the switch casing and from these connections cables are led away through terminals of the same character as illustrated and described in reference to Figures 1 to 3.

The terminals in this modified form are mounted in the rear part or cover 80 of the shield housing, which, though a separate member, is in substance a continuation of the cylindrical base housing 50, and which is secured upon the base housing 50 by screws 8| extending into threaded bosses 62 in the base housing. Optionally a gasket 63 may be employed to seal the base portion 50 and the cover portion 60 of the shield housing.

In both forms of my invention the terminals are locked securely to the shield housing securing an efllcient and satisfactory connection with the switches and providing a moisture-proof entry of the cable into the housing as well as a complete grounding of the metal cable shielding to the housing.

Thus I have achieved a battery and magneto switch shield assembly, the switch of which assembly is completely enclosed in a structural sense as a protection against water, oil, and dirt, and completely shielded electrically by a housing which has high conductive properties and which is positively connected with the cable shielding serving to dissipate into the ground all electrical radiations occurring in the unit.

Although I have herein shown and described my invention in what I have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope or the claims so as to embrace any and all equivalent structures.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In combination with a battery and magneto switch which includes a switch casing enclosing the movable contact elements of the switch and a flush mounting flange extending from the easing, a shield adapted for flush mounting on a panel comprising a housing of substantially high conductive properties enclosing the switch casing and having an opening in one end for the easing to extend through but not large enough for the switch casing flange to pass through, an annular flange bounding said opening and having a face in overlapping engagement with the switch casing flange, means adapted to clamp the switch mounting flange upon the said face of the housing flange, and moisture-proof and water-proof cable terminals and cables entering the housing said cable terminals establishing an electrical connection between the housing and metal shielding on the cables.

2. In combination with a battery and magneto switch which includes a switch casing enclosing the movable contact elements of the switch and a mounting flange extending from the casing, a shield adapted for flush mounting on a panel comprising a housing of substantially high conductive properties enclosing the switch casing and having an opening in one end for the casing to extend through but not large enough for the switch casing flange to pass through, an annular flange bounding said opening and having a face in overlapping engagement with the switch casing flange, means adapted to clamp the switch mounting flange upon the said face of the housing flange, and moisture-proof and water-proof cable terminal and cables entering the housing said cable terminals establishing an electrical connection between the housing and metal shielding on the cables, said housing being provided with a removable section rearwardly of the housing flange by which access may be obtained to connections between cables and the switch, and said housing providing a water-proof and moisture-proof enclosure for said switch casing.

3. In combination with a battery and magneto switch which includes a switch casing enclosing the movable contact elements of the switch and an annular mounting flange extending radially from th casing, a shield adapted for flush mounting on a panel comprising a housing of substantially high conductive properties enclosing the switch casing and having an opening in one end for the casing to extend through but not large enough for the switch casing flange to pass through, an annular flange bounding said opening and having a face in overlapping engagement with the switch casing flange, means adapted to clamp the switch mounting flange upon the said face of the housing flange, means adapted to attach said housing flange upon said panel, and moisture-proof and water-proof cable terminals and cables entering the housing said cable terminals establishing an electrical connection between the housing and metal shielding on the cables. 

